On Thu, Jun 29, 2023 at 5:25 PM Hawkins Jiawei <yin31...@gmail.com> wrote: > > According to VirtIO standard, "The driver MUST follow > the VIRTIO_NET_CTRL_MAC_TABLE_SET command by a le32 number, > followed by that number of non-multicast MAC addresses, > followed by another le32 number, followed by that number > of multicast addresses." > > Considering that these data is not stored in contiguous memory, > this patch refactors vhost_vdpa_net_load_cmd() to accept > scattered data, eliminating the need for an addtional data copy or > packing the data into s->cvq_cmd_out_buffer outside of > vhost_vdpa_net_load_cmd(). > > Signed-off-by: Hawkins Jiawei <yin31...@gmail.com> > --- > v2: > - refactor vhost_vdpa_load_cmd() to accept iovec suggested by > Eugenio > > net/vhost-vdpa.c | 42 ++++++++++++++++++++++++++++++++---------- > 1 file changed, 32 insertions(+), 10 deletions(-) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 6f6a5c6df6..0bd1c7817c 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -620,29 +620,43 @@ static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState > *s, size_t out_len, > } > > static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class, > - uint8_t cmd, const void *data, > - size_t data_size) > + uint8_t cmd, const struct iovec *data, > + size_t data_len) > { > const struct virtio_net_ctrl_hdr ctrl = { > .class = class, > .cmd = cmd, > }; > + void *cursor = s->cvq_cmd_out_buffer; > > - assert(data_size < vhost_vdpa_net_cvq_cmd_page_len() - sizeof(ctrl)); > + /* pack the CVQ command header */ > + assert(sizeof(ctrl) < vhost_vdpa_net_cvq_cmd_page_len() - > + (cursor - s->cvq_cmd_out_buffer)); > + memcpy(cursor, &ctrl, sizeof(ctrl)); > + cursor += sizeof(ctrl); > > - memcpy(s->cvq_cmd_out_buffer, &ctrl, sizeof(ctrl)); > - memcpy(s->cvq_cmd_out_buffer + sizeof(ctrl), data, data_size); > + /* pack the CVQ command command-specific-data */ > + for (int i = 0; i < data_len; ++i) { > + assert(data[i].iov_len < vhost_vdpa_net_cvq_cmd_page_len() - > + (cursor - s->cvq_cmd_out_buffer)); > + memcpy(cursor, data[i].iov_base, data[i].iov_len); > + cursor += data[i].iov_len; > + }
Can we replace all of the above by iov_to_buf? > > - return vhost_vdpa_net_cvq_add(s, sizeof(ctrl) + data_size, > + return vhost_vdpa_net_cvq_add(s, cursor - s->cvq_cmd_out_buffer, > sizeof(virtio_net_ctrl_ack)); > } > > static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n) > { > if (virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_CTRL_MAC_ADDR)) > { > + const struct iovec data = { > + .iov_base = (void *)n->mac, > + .iov_len = sizeof(n->mac), > + }; > ssize_t dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MAC, > > VIRTIO_NET_CTRL_MAC_ADDR_SET, > - n->mac, sizeof(n->mac)); > + &data, 1); > if (unlikely(dev_written < 0)) { > return dev_written; > } > @@ -665,9 +679,13 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s, > } > > mq.virtqueue_pairs = cpu_to_le16(n->curr_queue_pairs); > + const struct iovec data = { > + .iov_base = &mq, > + .iov_len = sizeof(mq), > + }; > dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_MQ, > - VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, > &mq, > - sizeof(mq)); > + VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET, > + &data, 1); > if (unlikely(dev_written < 0)) { > return dev_written; > } > @@ -706,9 +724,13 @@ static int vhost_vdpa_net_load_offloads(VhostVDPAState > *s, > } > > offloads = cpu_to_le64(n->curr_guest_offloads); > + const struct iovec data = { > + .iov_base = &offloads, > + .iov_len = sizeof(offloads), > + }; > dev_written = vhost_vdpa_net_load_cmd(s, VIRTIO_NET_CTRL_GUEST_OFFLOADS, > VIRTIO_NET_CTRL_GUEST_OFFLOADS_SET, > - &offloads, sizeof(offloads)); > + &data, 1); > if (unlikely(dev_written < 0)) { > return dev_written; > } > -- > 2.25.1 >